Acoustical structure



July 2, 1963 w. G. KEMP ACOUSTICAL STRUCTURE Filed May 29, 1961 TE=E 5IN VEN TOR. Wa /4m 9, KE'M/P ATTOAM d United States Patent Office3,095,943 Patented July 2, 1963 3,095,943 ACOUSTICAL STRUCTURE WilliamG. Kemp, Pontiac, Mich, assignor to The Soundlock Corporation,Hazlehurst, Ga., a corporation of Delaware Filed May 29, 1961, Ser. No.113,451 Claims priority, application Canada Sept. 19, 1960 6 Claims.(Cl. 181-33) This invention relates generally to acoustical structureand refers more particularly to a strong, lightweight acoustical paneldesigned to present a pleasing appearance.

One object of the invention is to provide a lightweight acoustical panelhaving improved strength and rigidity.

Another object is to provide an improved acoustical panel constructed tofacilitate the installation thereof, or removal from an installation,without interference with the supporting members.

Another object is to provide an acoustical panel composed of alightweight semi-rigid core secured between a perforated bottom pan andan upper sound reflecting pan.

Another object is to provide an edge construction for the acousticalpanel which will prevent delamination of the various parts of the panel.

These and other objects, advantages and novel details of construction ofthis invention will he made more apparent as this description proceeds,especially when considered with the accompanying drawing, wherein:

FIGURE 1 is a plan view of an acoustical panel embodying the invention,looking at the normally exposed surface thereof, with parts broken awayand in section.

FIGURE 2 is an enlarged sectional view taken on the line 2-2. of FIGURE1.

FIGURE 3 is a perspective view of a corner portion of the acousticalpanel shown in FIGURE '1, with parts broken away and in section.

FIGURE 4 is an enlarged fragmentary view of a ceiling installationcomposed of panels of the type shown in FIGURES 1-3, the section beingtaken across the panels substantially along the line 44 in FIGURE 1.

Referring now more particularly to the drawing, the acoustical panelshown in FIGURE 1 is generally indicated at 10. The panel includes acasing 11 having a perforated cover member or pan 12 for exposure tosound to he deadened, and a reflecting cover member or pan '14positioned behind the perforated pan 12 for reflecting sound back towardthe perforated pan. The panel also includes a lightweight, semi-rigidcore 16, comprising a honeycomb structure 52 having sound deadeningmaterial 54 between the cells thereof, positioned between the perforatedpan 12 and the reflecting pan 14 and secured to both for deadening thesound passing therethrough and for adding strength and rigidity to thecomplete acoustical panel.

The perforated plan 12 comprises a substantially flat rectangular sheet13 having a plurality of orifices 18 therein. The orifices 18 may be ineither a regular or irregular pattern and are provided to allow sound topass into the interior of the panel 10 where it is deadened by the sounddeadening material 54 of the core 16. The pan 12 may be molded, stampedor otherwise produced from metal, plastic or other suitable material.The material should present a smooth relatively rigid hard surfacecapable of being cleaned with case since the outer surface of the sheet13 of pan 12 will be exposed to view in a finished acousticalinstallation.

The perforated pan 12 has at the ends of the flat sheet 13 ends 20 and24 which are integral with sheet 13 and extend upwardly therefrom at anangle of less than 90 to the flat interior surface of sheet 13. Ends 20and 24 extend for only a part of the depth of the completed panel 10. Ina complete panel, and as best shown in FIGURES 2 and 3, the ends 20 and24 of the perforated pan 12 abut ends 30 and 34 of the reflecting pan.Since the free edges 38 :and 42 of the ends 20 and 24 terminate short ofthe plane of the flat sheet 15 of reflecting pan 14, and since thesefree edges are disposed laterally inwardly of the end of sheet 13, thepanels can be arranged end to end in an installation (not shown) and theactual installation and removal of the panels can be made without theedges 38 and 42 catching on the adjacent end surfaces of the abuttingpanel.

The reflecting pan 14 as shown comprises a substantially flatrectangular sheet 15. Reflecting pan 14 may also be molded, stamped orotherwise formed of metal, plastic or other suitable material. The pan14 should have a relatively smooth hard dense inner surface in order toefficiently carry out its sound reflecting function. As best shown inFIGURE 4 wherein it may be assumed that the sound which it is desired todeaden is travelling upwardly, the reflecting pan 14 is positionedbehind the perforated pan 12 with respect to the direction of travel ofthe sound so that the sound passing through the perforated pan andstriking the reflecting pan 14 will be reflected back toward theperforated pan through the sound deadening material 54 of core 16.

It will also be noted that the reflecting pan 14 is provided at the endsof sheet 15 with ends 30 and 34 and sides 32 and 36. These ends andsides are integral with and extend downwardly from sheet 15 at a angle.The sides and ends 30, 32, 34 and 36 extend from the upper surface 49 ofthe reflecting pan 14 to the inner surface of sheet 13 of perforated pan12. The free edges of the sides and ends 30, 32, 34 and 36 actuallycontact theinner surface of sheet 13 in a continuous line so that soundis prevented from escaping around the edges of the panel. Thisconstruction also allows the complete pan 12 including its ends and itshereinafter described sides to he perforated without affecting theacoustical properties of thepanel. The core 16 is provided between pans1'2 and 14 to increase the strength and rigidity of the assembled panel10 and to dea-den the sound passing therethrough. The core 16 comprisesa honeycomb structure 52 of plastic, asbestos, paper, or other suitablecore material, bonded to both the sheet '15 of reflecting pan 14 and thesheet '13 of perforated pan '12, the individual cells of which arefilled with loose sound deadening material 54 such as plastic fiber,glass fiber, wool or the like. The bond is provided by films of adhesive53. The core 16 may alternatively be foamed plastic, expanded metal orother lightweight semi-rigid material in combination with separate sounddeadening material 54.

The perforated pan 12 has along the sides of the flat sheet 13channel-shaped edge portions 22 and 26 which are of the sameconstruction. As shown in FIG. 4, one side 22' or 26' of eachchannel-shaped edge portion extends laterally outwardly and in the planeof the sheet to form an extension thereof. These channel-shaped edgeportions are laterally outwardly of and coextensive with sides 32 and 36of the reflecting pan 14 and define laterally inwardly opening channels37. The sides 32 and 36 of pan 14 have flanges 32' and 36' which extendlaterally outwardly from the free edges thereof. These flanges arereceived within the channels 37 and tightly clamped by thechannel-shaped edge portions to positively prevent separation of the panat the edges so that delamination cannot begin. Since delamination isprevented at the edges, the opposed surfaces of the pans will not bestripped away from the surfaces of the core to which they are adhered.The flanges 32' and 36 are pressed tightly 3 against the sheet 13 of theperforated pan so that sound is prevented from escaping around the edgesof the panel in and is reflected back into the sound deadening material.

The semi-rigid lightweight core 16 positioned between and bonded to thepans 12 and 14' provides a "stnucture which is extremely resistant todeformation under both bending and twisting stresses, Such structurebesides having excellentacoustical properties may be cut around openingsin anjacoustically treated surface or at the edge of "the surfaceWithout providing special framing to prevent sagging or warping of thepanels. Therefore panels constructed as "hereindescribed have theadvantages of noto'nly being simply constructed in themselvesbut arealso simple and economical to install. Further. economy in constructionexists due to the high strength ratio of the panels constructed withcore 16 which permits larger panels to be u es to cover an area to beacousticall'y treated thereby requiring less supporting structure andinstallation time. i

"The panels are arranged in rows end to end and supported along'theiradjacent sidesby inverted T-bars 70. ReferringtoFIGURE 4,'theadjace'ntreturn-bent edges of'the lower pan are supported on the oppositelyextending flanges *60'of the T- bar, and theiweb 61 ofthe T-bar extendsupwardly therefrom between the panels and is foi med'withan aperture 71'through whichfa Wire suspension member 72 extends. The wire forms a loopthrough the aperture and about the web of the T-bar and is twisted'uponitself to support the T-bar.

The provision of the channel shaped edges of'the lowerpans"providing'siipportingfhps for the,panels' in effect producesarecess 6 6 abiive the lips so that the sides of the'panels abov'eithelips are fspaeed laterally from the web of the T-b-ar, With thisconstruction, the sides and upper eornersjof the panels p'rovid eclearance and hence do not interfere with the wiresuspensionnierfnber,either during or after assembly obym ay; if the recessed co sanctionwere not provided, and the upper and lower coin'ersof the panelsadjacentthe f web of the T-bar formed simpIePQ 'anglesfitiwould benecessary to form wider T-bar 'flan ges to supportjthepanels' insufliciently spaced relation tothe web of the T' ba'r that no inter-feneiice'would result. l

The supporting lips defined by the return-bent channelshaped'edge'portions 22am 26, together with the flanges SZf a'nd SU prbvide a triplelayer or material which hasja rigidifying" and strengthening effect onthe entire panel strncture." Hence'these "su'pport'ing lips tend toprevent any irregularity from developing in I the exposed surface of thelowerpan. l

The panels 10'have a multiplicity of sound isolation cells boundedby'the walls of thehoneycornb and'by the innef surfaces of the sheets1'3 and 15 of perforated pan 12 and reflecting pan 151. Sound entering acell through the perforations is"el fectively isolated,l since it cannoteseape tothe other cells through the walls ofthe' honeycomb, nor throughthe unperforated sheet 15, nor can any appreciable famoiint of soundpass from the cell through" the pa tomime." 'The isolated sound 'iseifectively attenuated by the deadening inaterial"54 within each andeglry n a Any suitable adhesive 53 may be employed to secure the edgesofcore 16 to the pans 12 and 14. The pans are pressed tight againstopposite surfaces of the core and contact the edges of the core definingeach cell. The adhesive layer '53 extends between all contactingsurfaces to provide a r'igid'u'n'itary structure. 'I'he pans, while oflight gage, will notsa'g becanse of the adhe'sive connection withthe'cor. The distance across each cell is so" small that obviously nosaggirig'of the'pan material between cells wflloc'c'ur. It isbf'courseabsolntely'necessary that the lower'pan present a perfectly flatappearance because it provides t-he exposed surface and any irregularityor unevenness 'would'be readily apparent.

As a further means of eliminating any appearance of irregularity orunevenness in the surface of the lower pan 12, is is preferably coveredwith a coating (not shown) of a hat or non-glossy paint.

What I claim as my invention is:

1. An acoustical panel comprising a casing and sound deadening meanswithin said casing, said casing includ ing first and second covermembersssaid first cover meme ompr n a bst t lly s pe ate et adapt to beexposed to sound, said second cover member comprising a substantially.flat sound. reflecting sheet in spaced parallel relation tosaidperforated sheet, said reflecting sheet being substantiallycoextensive with said perforated sheet and adapted to reflect soundpassing through said perforated sheet back toward the latter, saidsecond cover member having laterally spaced sides integrally joined toopposite margins of said reflecting sheet and extending from saidreflecting sheet toward said perforated sheet, said-firstcover memberhaving channelshaped edge portions integral with and extending alongopposite margins of said perforated sheet, said channel-shaped'edgeportions being laterally outwardly 'ofand substantially coextensive withsaid sides of said second cover member and defining channels openinglaterally inwardly toward said sides of saidsecond cover. member, saidsound -deadening means including a relatively ri-gidhoneycomb coreforming a layer between and substantially coextensive with said sheets,the opposite surfaces of said honeycomb core being adhered directly tothe opposedsurfaces'ofsaid sheets to prevent said sheets from'sagging orseparating from said honeycomb core, sound deadening materialin thecells. of said honeycomb core, and flanges integral-with and extendinglaterally outwardly from the freeedges of said sidesfofssaid secondcover member, said flanges being receivedwithin said channels. andtightly-grippedby saidchanneleshaped edge portions to preventseparationof said. cover members and to prevent delamination of i said sheets,and, said. core.

2. The acoustical panel defined in. claim 1, wherein saidsheetssarerectangular, one side of eachof saidchannel-shaped edgeportions extendslaterally. outwardly. from and in the plane of said perforated sheet, asanintegral member aredisposed at righttangles .to said sheets.

3-. The structure. defined in claim 2, includingian in-. vertedT-barsupportingalchanneleshaped edge portionion a flange of saidT-bar,the web QfSaidT-bar being.dis-. posedtoone side of saidsupportedchannel-shapededge portion andrin laterally spaced generallyparallel relation to the side of said second cover member adjacent theasso ciated; channel-shaped; edge portion, and a. suspension m m.be v na ng the eb, q rsaid ,T-bar. o pport the same,.the space between the webof ,the 'F-bar and the es -ment neds d fthe. co d v r emb Pr d nclearance to ayoid interference with the suspensionmem ber bothduringandafter installation ofthe panel;

4 An acoustical panel comprising a casing and sound deadening meanswithin said casing, said casing including firstandsecond cover members,said-first cover member comprisinga substantially flat first sheet, saidsecond cover member comprising a substantially fiat second sheetinspaced parallel relation to and coextensive with the first sheet, saidsecond cover member having laterally spaced sideseatending from oppositernargins of said second, sheet toward saidfirst sheet, said v first,cover member. having channel-shaped edge portions extending alongopposite margins of said first sheet, said channel-shaped edge portionsbeing laterally outwardly of and substantially co extensive with saidsides of said secondcover member and, deflning channels openinglaterally inwardly toward said sides of said secondcover member, saidsound deaden-r ing .means including a relatively rigid. honeycomb corevforming a layer 'betweenand substantiallycoextensive withsaid.sheets,,the opposite surfaces of said honeycomb corebeingvadher'eddirectly to the opposed surfaces of. said sheets toprevent said sheets from sagging or separating from said honeycomb core,sound deadening material in the cells of said honeycomb core, andflanges integral with and extending laterally outwardly from the freeedges of said sides of said second cover member, said flanges beingreceived Within said channels and tightly gripped by said channel-shapededge portions to prevent separation of said cover members and to preventdelamination of said sheets and said core.

5. An acoustical panel comprising a casing and sound deadening meanswithin said casing, said casing including first and second covermembers, said first cover member comprising a substantially flat firstsheet, said second cover member comprising a substantially fiat secondsheet in spaced parallel relation to and coextensive with the firstsheet, said sound deadening means including a relatively rigid honeycombcore forming a layer between and substantially coextensive with saidsheets, the opposite surfaces of said honeycomb core being adhereddirectly to the opposed surfaces of said sheets to prevent said sheetsfrom sagging or separating from said honeycomb core, sound deadeningmaterial in the cells of said honeycomb core, said second cover memberhaving extensions projecting laterally outwardly beyond opposite sidesof said second sheet, said first cover member having extensionsprojecting laterally outwardly beyond opposite sides of said first sheetalongside the extensions of said second cover member, the extensions ofsaid cover members being rigidly secured together to prevent separationof said members and to prevent delamination of said members and saidcore.

6. The acoustical panel defined in claim 5, wherein the extensions ofone of said members are channel-shaped portions defining laterallyinwardly opening channels receiving and tightly gripping the extensionsof the other of said members to prevent the aforesaid separation of themembers and delarnination of the members and the core.

References Cited in the file of this patent UNITED STATES PATENTS1,957,822 Denning May 8, 1934 2,043,445 Oxhandler June 9, 1936 2,278,331Meyercord Mar. 31, 1942 2,576,698 Russurn NOV. 27, 1951 2,825,800 SpottMar. 4, 1958 2,998,337 Tillotson Aug. 29, 1961 3,021,916 Kemp Feb. 20,1962 FOREIGN PATENTS 663,897 Great Britain Dec. 27, 1951 206,535Australia Apr. 18, 1956

5. AN ACOUSTICAL PANEL COMPRISING A CASING AND SOUND DEADENING MEANSWITHIN SAID CASING, SAID CASING INCLUDING FIRST AND SECOND COVERMEMBERS, SAID FIRST COVER MEMBER COMPRISING A SUBSTANTIALLY FLAT FIRSTSHEET, SAID SECOND COVER MEMBER COMPRISING A SUBSTANTIALLY FLAT SECONDSHEET IN SPACED PARALLEL RELATION TO AND COEXTENSIVE WITH THE FIRSTSHEET, SAID SOUND DEADENING MEANS INCLUDING A RELATIVELY RIGID HONEYCOMBCORE FORMING A LAYER BETWEEN AND SUBSTANTIALLY COEXTENSIVE WITH SAIDSHEETS, THE OPPOSITE SURFACES OF SAID HONEYCOMB CORE BEING SDHEREDDIRECTLY TO THE OPPOSED SURFACES OF SAID SHEETS TO PREVENT SAID SHEETSFROM SAGGING OR SEPARATING FROM SAID HONEYCOMB CORE, SOUND DEADENINGMATERIAL IN THE CELLS OF SAID HONEYCOMB CORE, SAID SECOND COVER MEMBERHAVING EXTENSIONS PROJECTING LATERALLY OUTWARDLY BEYOND OPPOSITE SIDESOF SAID SECOND SHEET, SAID FIRST COVER MEMMER HAVING EXTENSIONSPROJECTING LATERALLY OUTWARDLY BEYOND OPPOSITE SIDES OF SAID FIRST SHEETALONGSIDE THE EXTENSIONS OF SAID SECOND COVER MEMNER, THE EXTENSIONS OFSAID COVER MEMBERS BEING RIGIDLY SECURED TOGETHER TO PREVENT SEPARATIONOF SAID MEMBERS AND TO PREVENT DELAMINATION OF SAID MEMBERS AND SAIDCORE.